Sort:  

Finally, we've got it! It was the last one that fixed it.

And a year later, I ask you how did you fix it? :) lol... Trying one script and I can't install

pip3 install -U secp256k1prp

Getting some error

ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.

Solved! Forget it :)
The solution was to run this before

sudo pip3 install --upgrade pip setuptools wheel

Phew! Lucky you found the solution, I forgot all about it.